Device for saving precious metals



A. CHRISTENSEN.

DEVICLFOR SAVING PRECIOUS METALS.

APPLICATION FILED JAN. 19, 1920.

1,371,409, Patented Mar. 15,1921

INVENTOR.

Aasald (fizz'sielwen BY Q A TTORNEY PATENT OFFICE.

A-AS'U'LD CH RISTENSEN, OF STOCKTON, CALIFORNIA.

DEVICE FOR SAVING PRECIOUS METALS.

Specification of Letters Patent.

Applicationfiled January 19, 1920. Serial No. 352,517.

To all whom it may concern:

Be it known that I, AASULD CHRISTENSEN, a citizen of the United States, residing at Stockton, county of San Joaquin, State of California, have invented certain new and useful Improvements in Devices for Saving Precious Metals; and I do declare the following to be a full, clear, and exact de-' scription of the same, reference being had to the accompanying drawings, and to the characters of reference marked thereon, which form a part of this application.

This invention relates to improvements in concentrating or precious metal saving devices, being particularly intended to be used when extracting the metals from sand, gravel and the like with the aid of a stream of water.

The principal object of the invention is to provide a saving device adapted to be operated in conjunction with the ordinary water-filled sluice box, which will save and concentrate a far greater percentage of the precious metals than is possible with the ordinary sluice boxes and concentrators.

Another object is to provide a device for the pur ose which may be connected to a standar sluice box with but very few alterations being necessary on the latter.

A further object of the invention is to produce a sim lo and inexpensive device, and yet one which will be exceedingly effective for the purposes for which it is designed.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following-specification and claims.

In the drawings similar characters of reference indicate corresponding parts in the several views.

Figure 1 is a sectional elevation of the device, showing the same in connection with a standard sluice box.

Fig. 2 is a top plan section taken on a line 2-2 of Fig. 1.

Referring now more particularly to the characters of reference on .the drawings, the numeral 1 denotes the main sluice down which the metal-bearing sand or gravel is being washed, being provided for a majority of its length with the ordinary transverse rifiies 2, and sloping downwardly as is a common custom.

At the termination of these riflies a horizontal transverse plate 3 extends for a certain distance on a level with the floor of the sluice, there being a space 4 under the plate between the same and the bottom of the sluice, shut 011 on three sides from the same. water pipe 5 projects into the space or chamber 4 centrally of the width thereof and adjacent its inception, and opens upwardly, so that when water under pressure is forced through this pipe, it will strike the under side of the plate 3 and be deflected the entire Width and length of the chamber. At the down or after end of the plate 3 are a plurality of transverse narrow plates or riflles 6, positioned in parallel order, but angled slightly relative to the length of the sluice 1. These rifiies are arranged in the form of steps, the one adjacent the plate 3 being above the next one, and so on, so that at the adjacent edges of any two of said riflies a naroW slit 7 therebetween is had.

Under these rifiles is a sheet 8 of what is known as expanded iron, below and adj acent which is a layer 9 of cocoa matting or burlap, the sheet 8 being on a level with the floor of the sluice 1 under the chamber 4.

A discharge 10, substantially the width of the box 1, is positioned thereunder adjacent and below the lowermost of the riflles 6, such discharge emptying into a well 11 having its sides sloping inwardly toward the bottom, and provided at that point with a catch bowl 12 having a removable plug 13 in the bottom thereof. I

The well 11 has anoverflow chute 14 sloping downwardly therefrom, and provided over a'portion of its length with transverse bars 15, suitably spaced apart, and being wider at the top than at the bottom to prevent clogging up. Beyond these rlifies 1s a guard plate/16 depending downwardly from the bottom of the chute 14.

Under the said chute is a funnel shaped receptacle or tank 17 having a plurallty of vertically positioned riflles 18 therein terminating short of the bottom thereof.

A catch bowl 19 similar to the member 12 is secured to the bottom of the receptacle 17 Into the plug 19 therein is screwed a pipe 19", which projects upwardly through the bowl, leaving a clearance at the neck thereof, and terminating just above sald neck.

This pipe is always open, and discharges into a box, trough, or snnllar catch means positioned thereunder. It receives therein Patented Mar. 15, 1921. i

' from which a constant flow of the lighter of the solid materials suspended in the receptacle 17, the very heavy particles sliding down the sides thereof into the catch bowl 19, which may be emptied at intervals by removing the pipe 19 -and plug 19 as a unit.

A water supply pipe 20 is connected to the receptacle, at a point just below the lower ends of the rifles, and entering said funnel at a tan ent, as shown at 21.

A horlzontal deflector late 22 overhangs a portion of the receptac e 17 at the top of 'the same and a suitable distance above the rifles, being provided with an underhanging transverse Ii 23 along its inner edge. This plate is positioned relative to the pipe 20 so that it will be at the point of greatest swirl of the water rising from said pipe.

The plate 22, and likewise the receptacle about the top of the circular portion thereof, of course have straight side walls 24 so that the waterpassing over said plate will'positively discharge into a relatively shallow well 25 as does also the chute 14:, at the bottom of which well is a catchbowl 26. This well overflows into a chute 27, which may be provided with expanded iron 28 and matting 29 thereunder of the same design as the rifles 6.

After passing over this chute or'sluice, the

' water and gravel may well be considered to have been relieved of all metals therein, and hence this sluice may discharge into any waste runway or other place.

In operation, the metal bearing gravel first flows down the sluice 1, the major particles of metal being deposited against the rifles 2, as usual.

The water etc. then passes over the rifles 6, which impede the flow somewhat and cause some more particles of heavy matter to drop through the rifles, onto the expanded iron plate 8. The stream of water issuing from the pipe 5 carries the larger ones over said plate into the discharge 10, while the smaller particles pass through the plate and are held by the matting 9 thereunder.

The rifles 6 are preferably removable as a unit, so that the matting may be removed and the metal washed therefrom. This matting I have found to be especially serviceable in catching gold and platinum dust, and flowered quicksilver, which otherwise is lost.

Still in a state of agitation caused by the current of water from the pipe 5, the water under the rifles 6 and some of that above, passes down the discharge 10 and into the well 11, apercentage of the remaining particles of metal settling into the bowl 12, they may be removed when deslred.

The swirling overflow from the well passes into the sluice 14, over the bars 15 therein through which the greater percentage of the metals still remainin in the water drop into the funnel-tank 17. vhat particles are carried beyond the bars drop into the catch bowl 26 in the bottom of the well 25, the overflow from which flows into the sluice 27, catching the few particles of metal which remain if any.

The water and suspended metals dropping into the tank are diverted into the bowl 19 at the bottom thereof, while the water entering the tank on a tangent through the pi e 20 swirls around and up, thus thorough fy stirring or agitating the gravel and tending to free the heavier particles of metal therefrom. 7

Before overflowing from this tank into the well 25, the water must rise abovethe plate 22, and as stated, this is along the side of the tank at which the greatest upward swirl of water occurs.

Particles in suspension will therefore be caught by the lip 23 and again dropped into the tank instead of passing over the plate 22.

It will be noticed that from the very outset of my improved sluicing operation, I have endeavored to so construct and arrange the parts of the device that a constant swirling or agitation of the water is maintained at all states, thus tending to ositively break up and separate the grave etc. from the heavier metals, and so insuring that practically none of the latter will be lost.

From the foregoing description it will be readily seen that I have reduced such a do? vice as substantially ful ls the object of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described my invention what I claim as new and useful and desire to secure by Letters Patent is 1. A device for saving precious metals including a funnel shaped tank, a chute over the tank and discharging-thereinto over a considerable portion of the area of said tank, a catch bowl at the bottom of the tank, vertical rifles in the tank terminating short of the bottom, a pipe discharging water into the tank at a tangentto the sides thereof and at a point between the end of the rifles and the bottom, and a horizontal deflector plate projecting over the tank for a certain distance and above the rifles, said plate having an under-turned lip extending transversely thereof, the plate being positioned relative to the pipe at the point where the greatest surface-swirl of the water willoccur, whereby any articles of heavy material still suspended 1n the water are caught by the lip.

2. In combination with a funnel shaped tank adapted to receive water having suspended particles of metal therein, and prothe floor thereof, and a transverselip under vided with means for swirling-the water in said plate to catch'and return into the tank the tank to cause a current toward the top, a any particles of matter still suspended in 10 discharge chute surrounding the tank on the water and tending to flow over the chute .5 three sides and positioned thereabdve, a de-i therewith.

flector plate positioned across the tank adjar In testimony whereof I aifix m si ature. cent the open side of the chute and fon ning ,AASULD CHRIS E SEN. 

